Middlings-purifier



(.No Model.) 2 Sheets-Sheet 1. J. H. REDPIELD.

Middlings Purifier. No. 234,688. Patented Nov. 23,1880.

L Z7T 1/ 1 'IIIIIIII NJETERS. PNOTO-LITHGGRAPMER, WASWNGTON. D C.

(No Model.) I 2 Sheets-Sheet 2. J. H. REDFIELD.

' Middlings Purifier.

Paten'ted Nov. 23, 1880 74 127206000: haven-Z02 WMM/ JIM N. PETERS, PHOTO-LITHOGRAPHER, WASHINGTON, D C

JAMES H. REDFIELD,

A'IENT tries.

OF SALEM, INDIANA.

MIDDLINGS-PURIFIER.

SPECIFICATION forming part of Letters Patent No. 234,688, dated November 23, 1880.

Application filed July 1, 1880. (No model.)

To all whom it may concern:

- Be it known that I, JAMEs H. REDFIELD, a citizen of the United States, residing at Salem, in the county of Washington and State of Indiana, have invented certain new and useful Improvements in Middlings-Purifiers, of which the following is a specification.

My invention relates specially to middlingspurifiers which provide for the introduction of two currents or streams of air into the middlings-purifyin g chamber, one stream passing in above the sieve and the other below and up through the sieve, such purifiers being also provided with a spout for conducting the middlings up to and through the supply-passage, and a fan for elevating the middlin gs and producin g the two currents or streams of air introducedamid the middlings in the purifying-chamber. The invention, however, is applicable to purifiers which do not have the middlings introduced vinto them from a suction-spout, but spouted directly in at the top in an approved manner now in use; and the objects and nature of myimprovements will be fully understood from the following specification and accompanying drawings, in which- Figure 1 is a vertical longitudinal section of a combined middlings elevator and purifier,-

having a middlings-conducting spout, a suc tion-fan, and air-entrance passages above and below the sieve, as shown in Letters Patent granted to me on April 15,1879, and also having my present improvements applied to it. Fig. 2 is a horizontal section of the machine shown in Fig. 1. Fig. 3 is a partial horizontal section of the machine shown in Fig.1, the section being taken on a lower plane than Fig. 2. Fig. 4 is a vertical transverse section of the machine. Fig. 5 is an end elevation of the machine, looking at the supply or feeding end. Fig. 6 is a detail section of the hanger and support of the sieve. I

Similar letters of reference in the several figures indicate corresponding parts.

A represents the suction spout through which the middlings are elevated from a floor below, or the same floor upon which the purifier is situated, and discharged into the purifyin g-c'hamber B of the purifier.

O is the spreading-board, which diffuses and deflects the middlings down upon the sieve D.

E and F are air inlets or passages, the one E being above the sieve, and that F below the slatted bottom D of the sieve-frame D The passage E receives into it the upper end of the suction-spout, and the passageF is provided with a wind-regulating slide, F.

G is an opening into a chamber, G, on top of purifier, and in communication with the suction-fan H. The chamber G is provided with arresting-strips a, whereby light impurities passing up with the air are trapped into the chamber, while the air has freedom to pass to the fan-case H. G is also an air-passage leading from the purifier into the fan-case.

I are passages for air between the lapping edges of the slatted bottom of the frame of the sieve. J are wind-breakers arranged across the sieve, one just in rear of each of the passages I, so that the air which enters a passage forward of a wind-breaker, J, will be arrested by the wind-breaker forward of said passage. Thus the air introduced into the tight chamber B of the purifier through the passage F is divided up and thrown against the sieve-cloth and forced through its meshes in such a manner that impurities above the sieve will be held up and carried over the end of the sieve into the chute-discharging receptacle K.

L is a longitudinal central partition on the bottom of the sieve-frame for dividing up the surface upon which the purified middlings fall into numerous chambers or sections, and also dividing the wind-currents longitudinally.

M is a trough placed centrally beneath the slatted bottom of the sieve-frame. This trough is narrower than said bottom, and is of a length sufficient to catch the purified middlings and the tailings. At its discharging end it is divided horizontally into two channels, and the lower one of these channels, I), connects with a middlings-discharge chute, K, while the upper channel, I), connects withlthe return-mid in gs c are formed on each side of the partition L, and by means of these openings the purified middlings and the return middlings are discharged into the respective channels of the trough, and thence into the discharging chute-receptacles K K Any required number of the slats may be provided with openings 0 The slide N is operated through the airpassage 13, and by moving this slide toward the spout K the cut-off of the purified middlings is lengthened, and by moving it in an opposite direction the cut-off is shortened. Thus more or less purified middlin gs are permitted to pass into the lower channel of-the spout, or more or less middlings which are to be returned into the suction-spout, and thence back into the purifier for a second action upon them of the blast and sieve, are allowed to pass into the upper channel of said spout, and thence into the chute discharging-receptacle K The slats forming the bottom of the sieveframe are inclined downward from the respective sides of said frame, and form an inverted ridge directly over the trough, and thus the middlings flow laterally toward the center of the spout and then escape into the spout. By this construction the middlings are allowed to be spread by the board 0 over the entire width of the sieve-cloth, and yet can be discharged through the central trough.

The sieve-frame is provided with a lateral extension, d, of cotton or other flexible material, and by this extension it is tacked to the side walls of the purifying-chamber; and it is also provided with an end extension of the same material by which it is tacked to the feeding end of the purifier, as shown. The flexible extensions are left quite full or loose, in order that the sieve-frame shall have freedom to vibrate in any manner required. These extensions form a partition or diaphragm for pre' venting the middlings passing downward outside the frame, and air from passing upward except through the sieve-cloth.

The sieve-frame is supported and suspended by means of hanger-straps P and inclined ratchet-toothed brackets P. The straps are provided with knife-edge bearingsf, which are set in any one of the V-notches between the teeth of the brackets. By this construction of the hangers and brackets great facility for adjusting the sieve-frame more or less inclined, for the purpose of having the middlin gs travel either fast or slow over the sieve-cloth, are afforded.

The sashes D, containing the sieve-cloth, are made to slide'in and outward endwise upon the frame D and by this construction it is not necessary to remove the sieve-frame from the purifier when it is desired to clean .the sieve-cloth or repair the same.

Each of the chute discharging-rece .)tacles K K K is provided, as usual, with a self'opening and self-closing valve, g, and the returnmiddliug chute K may have a conductingspout, 0, leading back into the suction and conducting spout A, as shown.

The fan-shaft Q is, as usual, provided with an eccentric, q, which acts as a knocker for acting upon the spring-bumper 1" of said frame. The spring k of the bumper is placed loosely upon an angular bearing-plate, l, and its ends bear against angular slotted plates m, which are confined to the purifier-frame by set-screws a. By this arrangement of the spring, as the eccentric wears away, the slack can be taken up, and the spring thus kept at a uniform tension, and improper jars and noise thus prevented. I t is only necessary to loosen the setscrews, adjust the plates on and again tighten the said screws to accomplish the tension upon the spring. When a clamp, as ordinarily, is used around the eccentric, a very little wear enables the eccentric to play backward and forward, and produce noise and jar; and it" his clamp should be too tight it will cause heat and endanger the mill by tire.

A pulley on the fan-shaft is provided, as usual, for driving the purifier.

One of the leading difiiculties experienced with purifiers of middlings is that of the sieveeloth becoming clogged with the light sub stances which float in theatmosphere beneath the cloth, these substances being sucked up against the cloth, and by accumulating finally stop all the meshes thereof and cause the middlings to run over the tail end of the sieveframe, or, at least, interfere'seriously with the air acting perfectly upon the middliugs which are passing over the cloth. By my improvementto wit, the construction of the bottom of the sieve-frame of broad slats set slightly above one another, and made to overlap, as shown, and in connection with this construction providing wind-breakers in front of each broad and shallow wind-passage of the bottom of the sievc-frame-the difficulty is overcome, for the strong current of air striking the windbreakers will be directed with a whirling motion against every part of the sieve-cloth, and will blow off the light substances and keep the under side of the cloth clean; and, in addition to this operation, the strong wind-eurrents introduced above and below the sievecloth will hold up the tailings until they are carried over at the discharge end of the machine, and all light substances, dust, find, and other impurities, will be carried into the trap or chamber G on top of the purifier, from whence they may be removed through a door, or by lifting off the cap of the chamber.

The spreading-board is located just above the receiving end of the sieve-frame, and diag' onally opposite the air and middlings inlet passage E. It is curved in form, and extends across the sieve-frame. By this construction the middlings are uniformly spread over the sieve as well as directed downward upon its receiving end.

In some middlings-purifiers, where the suction-spout is not required or used, a tin tube,

say two inches in diameter, may connect with a forwardly-extended hopper on top of the machine, and the middlings may be spouted into the purifier at the feeding or front end. Underneath this tube, and flexibly connected to the frames of the sieve and purifier, a transverse board, with its back edge slightly turned up or lipped, is placed, and the middlings, by piling up on this board, gradually flow over its edge upon the sieve in a somewhat spread or diffused state. I contemplate applying my improvements in connection With such feeding devices of purifiers, and therefore 'do not limit myself to the suction-spout for elevating the middlings.

YVhat I claim as my invention, and desire to secure by Letters Patent, is

1. The combination of the slatted perforated bottom of the sieve -frame, central trough provided with two channels, I) b, and a sliding cut-off device, N, substantially as and for the purpose described.

2. The combination of the endwise-removable sashes of the sieve-cloth and the sieveframe attached to the frame of the purifier by a flexible diaphragm firmly fastened to said frame, substantially as and for the purpose described.

3. The combination of the sieve-frame, han ger-straps having knife-edge bearings, and the inclined toothed-brackets, substantially as and for the purpose described.

4. The bumper-spring 7c of the purifier, in combination with the plate I, slotted plates m, set-screws n, eccentric q, and bumper 'r of the sieve-frame, substantially as and for the purpose described.

5. The combination of the sieve having a frame formed of slats at its bottom, and provided with a central trough and transverse partitions or wind-breakers, witha casing provided with air-inlets above and below the sieve, and with a suction and conducting spout and a suction-fan, substantially as and for the purpose described.

JAMES H. REDFIELD.

Witnesses:

'HARTWELL H. DE PEW,

GEORGE E. CLARK. 

